Talk about the power of social media — one graduate student battling Stage IV colon cancer in Arizona found out his Aetna health insurance plan had exceeded his $300,000 limit.He took to Twitter to express his frustration as his medical bills continued to grow and it turns out someone very influential was listening — the CEO of Aetna, who has subsequently agreed to pay “every last penny” of the man’s medical expenses and agrees that the healthcare system is broken.